For GHD Reversal Trial Participants

Growth hormone is a chemical produced naturally in the body that helps to encourage growth.  Growth hormone deficiency (GHD) occurs when the part of the brain that secretes this hormone does not produce enough, resulting in short stature.  Most people with GHD are diagnosed when they are children. To try to make sure that they have enough growth hormone to continue to grow, they have daily injections of growth hormone. Recently, research has shown that when some children enter puberty they start to produce a normal amount of growth hormone of their own and so may not need the daily injections to continue to grow.  

Our research trial will recruit 138 young people from hospitals in the UK and Austria who have previously been diagnosed with GHD, but in whom tests have shown are now producing a normal amount of growth hormone of their own. The young people will be put into one of two groups – half will stop taking growth hormone medication, and half will continue taking growth hormone medication. Our trial is a ‘randomised controlled trial’. This means that the group each person is put into will be chosen at random by a computer, to make sure that the results are fair.

If our research shows that young people are making enough growth hormone to carry on growing themselves, it would be very important as it will free them from the burden of daily injections and from taking a medicine that they don’t need and could save money for the NHS.

Young people previously diagnosed with GHD who are now producing a normal amount of growth hormone may be invited to take part in the study.  To confirm a normal amount of growth hormone is being produced, injections will be stopped temporarily to carry out a growth hormone stimulation test.  

To join the trial, you must have entered puberty, and be aged between 8 to 15 years of age for females and 9 to 17 years of age for males.   

Young people entering the trial will be put in one of two groups.  One group will stop taking their growth hormone injections whilst the other group will continue with the injections.

On joining the trial, height and weight will be measured and blood samples taken (to check lipids and levels of growth hormone), as would occur at a routine GHD check-up.  In addition, a hand x-ray will be performed to measure skeletal growth.  Participants will also be asked to complete a short questionnaire called the CHU-9D to record how they feel about their life on the day of the appointment.

After this, 6 monthly visits will occur in line with routine clinical follow up at the hospital's Endocrine clinic. Height and weight will be measured, and blood samples taken at certain appointments to measure growth hormone levels and lipids.  Information will be collected on medication taken, and other healthcare visits such as GP visits and hospital admissions. Participants will also be asked to complete the CHU-9D again.

This follow up will continue until near final height is reached.  This is defined as growing at less than 2 cm per year, and a bone age of 14 (for females) and 16 (for males).  At this point, bone age will be confirmed through another hand x-ray.  It is expected that most young people will be followed up within the study for around three years, but because the end is determined by reaching near final height, the actual length of follow up may vary dependant on the individual.

At the end of the study a further growth hormone stimulation test will be carried out to see if growth hormone is needed as an adult. Any future care will be discussed at this point.

For those stopping growth hormone during the trial, if during follow up blood tests show growth hormone levels have become low, another growth hormone stimulation test will be arranged.  If this confirms growth hormone levels are low, then growth hormone injections will restart.

Whilst you may not directly benefit from taking part in the trial, it is hoped the information gained may help us to improve the treatment of young people with growth hormone deficiency in the future.

Participating in the trial is unlikely to cause unusual discomfort or side effects.  Blood samples will be taken which may cause discomfort, bruising or bleeding, but this is true for all blood samples taken for any purpose.  Blood samples would be taken as part of GHD clinical care regardless of participation in the trial. 

Two hand X-rays will be carried out during the trial, one more than in usual standard care.  As X-rays use radiation, this means that you will have exposure to more radiation than if you were not taking part in the trial. The X-ray use in this trial has been reviewed by two independent experts who have confirmed that the additional risk of any negative effects is extremely low.

For those within the group stopping growth hormone injections, growth will be monitored closely. If at any point low levels of growth hormone are suspected, they will be retested and growth hormone treatment restarted if necessary.  Doctors can also restart growth hormone at any time they feel there is a need for it.

Blood samples taken during the trial will not be stored, but the data produced will be stored as part of the clinical records at the hospital where care is based.  X-rays will be stored as part of the clinical records but, in addition, they will be transferred to Great Ormond Street Hospital (UK patients) or Kepler Universitätsklinikum (Austrian patients) for estimation of skeletal growth.  The transferred images will be securely deleted 60 days after receipt.

Any information collected for the GHD Reversal Trial will be kept strictly confidential in the same way as medical records. The information will be sent by the hospital care team to the GHD Reversal Trial office at the University of Birmingham Clinical Trials Unit, on paper and electronically, where it will be securely stored under the provisions of the General Data Protection Regulation and Data Protection Act 2018.  

The results and conclusions will be published in peer reviewed medical journals and presented at academic meetings.  A summary of the trial results will be made available to participants once the study is complete and published.

At the end of the trial, an anonymised dataset will be produced and made available for other researchers to use. Any personal data will not be made available but securely stored for 25 years after which the personal information will be securely destroyed.

The GHD Reversal Trial is being run by the Chief Investigator Professor Mehul Dattani at University College London. The study is being funded by the National Institute for Health Research Health Technology Assessment Programme (NIHR HTA) and Sponsored by University College London. The GHD Reversal Trial is being co-ordinated by the Birmingham Clinical Trials Unit at the University of Birmingham.